1. Field of the Invention
The present invention relates to a display device including a panel module in which a display panel and a driving circuit for the display panel are integrated, and in particular, relates to a display device capable of preventing undesired electromagnetic radiation from a panel module and electronic equipment in which the display device is used as a display portion.
2. Description of Related Art
Recently, as plate-type display elements that display information such as images and characters, various kinds of display panels including a liquid crystal panel, a plasma display panel (PDP), an organic or inorganic electro luminescence (EL) panel and a field emission display (FED) panel have been developed.
Generally, these various display panels are treated as panel modules in which a display panel for displaying information and a driving circuit for driving the display panel are integrated, and display predetermined information when a suitable power and a driving signal are input to the panel module. In the case where the display panel is a liquid crystal panel, a backlight that outputs illumination light required for displaying information on the non-light-emitting liquid crystal panel is incorporated on a back surface side of the liquid crystal panel as a part of the panel module. Then, the display device using the display panel is assembled so that the panel module is sandwiched by a front housing located on an image display surface side of the display panel and a back housing located on a back surface side thereof.
Besides the use as stationary-type displays such as a television receiver and a monitor of a personal computer, the display devices using these display panels often are used as displays of portable equipment such as a notebook computer, a personal digital assistant (PDA), a portable DVD player, an electronic dictionary, a game machine and a mobile telephone, by taking advantage of thinness and lightness.
However, in the display device using the display panel, there is a problem that undesired electromagnetic radiation occurring from the display panel itself or driving circuit of the display panel affects a human body or other electronic equipment near the periphery of the display device. For preventing such undesired electromagnetic radiation from the display device using the display panel, a method has been known in which, in order to form a conductive loop, a filter glass is disposed in front of the display panel, and the filter glass and a housing containing a panel module are connected electrically using a gasket (see JP 2006-053241 A).
The technology described in the above Patent Document has been developed for use in comparatively large, stationary-type display devices such as a television set. However, since the filter glass directly leading to an increase in weight of the display device is used, it is difficult to apply the above conventional technology to the display device that is used as the display portion of the portable equipment, for which compactness and lightness as a whole are strongly demanded. Further, in the portable equipment, for making the equipment more compact as a whole, circuit elements having other functions often are disposed on the periphery of the panel module (display portion). Therefore, it is important effectively to prevent the undesired electromagnetic radiation toward sides of the panel module for not affecting other functional elements.
The invention disclosed in the present application solves the above-mentioned conventional problem, and its object is to obtain a display device in which measures are taken for preventing a situation that undesired electromagnetic radiation from a display panel and a driving circuit for driving the display panel do not affect an electric circuit disposed on the periphery of the display device, and electronic equipment including such a display device as a display portion.